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cell membrane
controls what enters and leaves the cell
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glucose
energy source for plants to make their own food
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oxygen
the colourless gas which plants produce during photosynthesis
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chloroplasts
the small structures inside a cell where photosynthesis takes place
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cell sap
a micture of sugras and water found inside a vacuole
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photosynthesis is a chemical reaction and so has a rate . the rate of photosynthesis varies depending on the three main factors :
- light
- carbon dioxide
- temperature
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light energy has to be absorbed by .... for photosynthesis to take place . the ..... the light , the more light energy there is . more light energy means that the rate of photosnthesis is .....
- chlorophyll
- brighter
- faster
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carbon dioxide is on eof the raw materials used by plants to make their food . the concentration of carbon dioxide in the air (....) is actually quite low
0.03%
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more carbon dioixde means
more photosnythesis , so plants make more food and crow quicker
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photosynthesis is controlled by
enzymes
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enzymes usually work best at
warmer temperatures . if the temperature gets too hot above 40°C , plant enzymes begin to break down and are destroyed or denatured
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what is the ideal combination of factors for the maximum rate of photosynthesis
- enough light
- enough carbon dioixde
- ideal temperature (not too hot or too cold)
- if one of the factors is restricted , the rate of photosynthesis will be below the maximum possible rate
- the restricted factor controls how quickly photosynthesis occurs and so limits the rate . It is called the limitating factor
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annote the below graphy to show how the amount of light affects the rate of phtosynthesis
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annote the below graphy to show the amount of carbon dioxide affects the rate of phtosynthesis
- at A carbon dioxide is the limitating factor
- at B carbon dioixde stops becoming the limitating factor and now temperature or carbon dioxide is the limitating factor
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annote the below graphy to show how temperature affects the rate of phtosynthesis
- at A temperature is a limitating factor
- at B temperature stops becoming a limitating factor
- at C once the temperature exceeds this optimal temperature, the enzyme begins to denature, thus lowering the rate at which photosynthesis occurs , so once again temperature is a limitating factor
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glucose is used in respiration to make
- energy
- glucose + oxygen --> (energy) + carbon dioxide + water
- (waste) (waste)
- energy is used to build new cells for growth or repair of damaged cells . some energy is used in chemical reactions to change some materials into others . more energy is used to move materials around inside the plant
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glucose can be used in proteinsynthesis
- all living cells need proteins to form enzymes and cell membranes . they also need proteins for growth . plant and algal cells can synthesize proteins from glucose and other raw materials such as nitrates . soluble nitrates can be absorbed through cell membranes from soil or water (if the plant is aquatic)
- glucose + nitrogen --> proteins
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glucose can be converted to starch
a plant wont use all the glucose it makes straight away . Some glucose needs to be converted to starch and stored for times when the plant cant make enough glucose , for instance when it's cold .
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why is starch an energy store
because the plant can change the starch back to glucose when it needs more energy (glucose) for respiration
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why is stracj useful for storage
its insoluble and large so cant diffuse through the cell membrane and wont react easily with other chemicals in the cytoplasm
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where is starch stored in cabbage
in the leaves
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where is tsrach stored in carrots
in the roots
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where is strach stored in brocili
in the flowera
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where is strach stored in potatoes
potatoes are stem tubers full of starch
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glucose is converted into lipids
some seeds , plants and algae store energys as fat or oil droplets in the cytoplasm . Fats and oils belong to a group called lipids .1g of lipid has a higher energy content than 1g of carbohydrate . lipids provide more glucose for respiration than carbohydrates , such as starch , when cells need it for respiration
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glucose is used for the photosynthesis of cellulose
when large molecules of cellulose are synthesized many molecules of glucose are linked together to form strong fibres . this makes cellulose a useful strcutural material in plant and algal cell walls . it strengthens the cell wall and prevents the cell wall bursting when it absorbs water . cellulose can be used to make and repair cells
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the faster the rate of photosynthesis , the
better the growth of the plants , the higher the yield . Yield is the amount of crop a plant produces .
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growers can get plants photsyntehsizing all year round . they can do this by
enhancing light , carbon dioxide concentration and temperature
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what are hydrophonics
in hydrophonics the water , nutrients and air needed by the plant to grow are delivered straight to the plants roots , freeing the plant to use its available energy in its upper leaf , fruit or flower development . In short this allows you to crow up to 10* the yeild , in half the space and half the time
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